Oil-insulated transformer



Jan. 4, 1927. 1,613,412

W. SARFERT ET AL OIL INSULATED TRANSFORMER Filed Dec. 19, 1923 FIG-4.

Patented Jan. 4, 1927.

UNITED STATES PATENT OFFICE.

WILLY SARFEBT, OI DBESDEN, AND FRIEDRICH HKBERLE, OF ZSCHIEBEN, NEARDRES- DEN, GEBIANY, ASSIGNORS TO SACHSENWERK, LICHT- UND KBAFT- AKTIEN-GESELLSCHAFT, F NIEDERSEDLITZ N/DRESDEN, SAXONY, GERMANY.

OIL-INSULATED TRANSFORMER.

Application filed December 19. 1983, Serial No. 681,466, and in GermanyJune G, 1823.

This invention relates to an improvement in oil insulated transformersorlike electri cal apparatus. Heretofore, in apparatus of this kind, inorder to maintain the apparatus 6 filled with an insulating fluid and toprovide for the expansion and contraction thereof, independent anextraneous compartments and chambers have been employed in someinstances, while in other instances to insure 1 the upper portion of thechamber being filled an auxiliary chamber has been employed in which agas under pressure has been used for this purpose,

The object of our invention is to provide a simple means for preventingthe accumulation of dangerous or noxious gases in the insaluting chambercompartment of an apparatus of the type to which the invention relatesby the use of a bushing having a sufliciently large bore therein topermit of the expansion and contraction of the insulating liquid orfluid under atmospheric pressure, as will behereinafter moreparticularly described.

In the drawing:

Fig. 1 is a sectional elevation of a transformer made in accordance withour invention, and

Fig. 2 is a similar view showing another form of transformer.

Referring to the drawing and particularly to Fig. 1, in carrying out ourinvention we employ a suitable receptacle comprising a vessel 10 adaptedto receive and contain a transformer 11 or other similar apparatus andto be filled with oil or other similar liquid insulating material asindicated at 12. This vessel is provided with a cover 13 which may beattached and secured thereto in any suitable manner.

Passing through the cover 13 there are chamber in each bore issufiiciently large to permit the insulating liquid to rise therein andto provide for the expansion and contraction of the liquid due to therise and fall in the temperature of the apparatus and this expansion andcontraction takes place under atmospheric pressure due to the fact thatthe outer ends of the bushings are open to the atmosphere by way ofports 18 19'. The leads 20 and 21 from the coils of the transformer, aswill be understood, and as is illustrated in this figure of the drawing,pass through the bushings and may be connected to terminals provided forthis purpose on the outer ends of the bushings.

A somewhat similar transformer of a different type, however, isillustrated in Fig. 2. In this structure the vessel or receptacle isdesignated at 22. This is provided with a cover 23 suitably connectedthereto and to which the core 24 of the transformer is suitably secured.The bushing in this structure is indicated at 25 and is mounted in aflange 26 provided for this purpose in the cover 23. The winding of thecore of the transformer in this structure is indicated at 27 and theends thereof as indicated at 28 and 29 are passed through the chamber 30in the bushing 25, this chamber 30 being of suilicient extent to permitthe oil or other liquid insulating material contained in the receptacle22 to expand and contract therein under the changes of temperature in amanner similar to that hereinbefore described in the form of theinvention shown in Fig. 1, the outer end of the bushing 25 being open tothe atmosphere so that this expansion and contraction takes place underatmospheric pressure.

We claim as our invention:

1. In an apparatus of the class described, a casing, an insulatingliquid filling the casing, and a hollow open ended bushing extendingupwardly from the casing and downwardly into the casing and adapted toprovide for the expansion and contraction of the insulating liquidwithin the casing under atmospheric conditions.

2. In an apparatus of the class described, a casing, a transformerwithin the casing, an insulating liquid filling the casing, and abushing extending upwardly from the easing and downwardly into theliquid within the casing, the said bushing having a bore of sufiicientdiameter to provide a chamber of suflicient capacity to permit theinsulating liquid to expand and contract under atmospheric conditionsdue to the rise and fall of the temperature of the apparatus.

3. In an apparatus of the class described, a casing, an insulatingliquid filling the casing, hollow open ended bushings extending upwardlyon the casing and downwardly into the casing and adapted to provide forthe expansion and contraction of the insulating liquid within the casingunder atmospheric conditions, and a transformer submerged in theinsulating liquid within the casing and having the leads of its windingspassing through the said bushings and con- 4. In an apparatus of theclass described,

nected to terminals at the outer ends there a comprising a bod and acover therefor, an insulating liqui filling the casing bushin extendingupwardly from the casing and ownwardly into the hquid withe in thecasing, the said bushings each having a bore of suflicient diameter toprovide a chamber of suflicient capacity to ermit the insulating li uidto expand an contract under atmosp eric conditions due to the rise andfall of the temperature of the apparatus, and a transformer secured tothe said cover and submer ed in the insulating liquid in the casing andhaving the leads of its windings passing through the said bushin andconnected to terminals at the outer end: thereof.

e In testimony, that we claim the foregoing as our invention we havesigned our names.

WILLY SARFERT.

FRIEDRICH HKBERLE.

